With computer assisted surgery, e.g. surgical navigation or robotics, pre-operative imaging studies of the patient can be used. The imaging studies can be displayed in the OR on an external computer monitor and the patient's anatomy, e.g. landmarks, can be registered in relationship to the information displayed on the monitor. Since the surgical field is in a different location and has a different view coordinate system for the surgeon's eyes than the external computer monitor, hand-eye coordination can be challenging for the surgeon.